This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Over the last year we completed our analyses of changes in NK cells in SIV-infected animals and published two manuscripts. These results show that SIV infection upregulates cytotoxic activity of NK cells and shifts homing from lymph nodes to the gut.